Conventionally, an electronic module such as a transfer power module is provided with a heat dissipation plate (heat dissipation layer) composed of copper, etc., on the back side of the electronic module in order to cool down electronic elements, etc., equipped in the electronic module (see, for example, JP 2015-211524A). When the heat dissipation layer is thus provided, a conductor layer, an insulating substrate, and the heat dissipation layer may act as a capacitor (a capacitor function may be formed). When the capacitor function is thus formed, noise caused by an electronic element in the electronic module may be emitted outside the electronic module through the heat dissipation layer.